Abstract:
Two-dimensional (2D) van der Waals (vdW) materials have recently emerged as a captivating class of compounds with unique electronic, magnetic, and structural properties. Among these, chromium tellurium thin films have attracted significant attention due to their intriguing combination of structural and magnetic characteristics. This study presents a comprehensive investigation of the synthesis, characterization, and magnetic behavior of epitaxial Cr2Te3 films, with a focus on their potential applications in the fields of spintronics and opto-spintronics.
Structural analyses, including electron diffraction and X-ray diffraction (XRD), reveal that the epitaxial Cr2Te3 films possess a hexagonal crystal structure with a pronounced orientation along the c-axis. X-ray photoemission spectroscopy (XPS) analysis provides insights into the electronic structure, core-level binding energies, and elemental composition of the chromium tellurium thin films, highlighting the prevalence of Cr3+ oxidation states, consistent with x-ray magnetic circular dichroism (XMCD) results.
Magnetic properties of Cr2Te3 films are probed using superconducting quantum interference device (SQUID) magnetometry. These investigations unveil intriguing magnetic behavior, notably perpendicular magnetic anisotropy (PMA) with a Curie temperature (TC) of approximately 150 K. The observed magnetic anisotropy is closely correlated with the crystal orientation of the films. Furthermore, optical magnetic circular dichroism (OMCD) spectroscopy is employed to study the optically induced magnetic responses of Cr2Te3 films. The OMCD results (Fig.1) confirm the presence of PMA in Cr2Te3 films with a TC in the range of 140~160 K, consistent with SQUID measurements. Notably, a substantial OMCD effect is observed, particularly in the deep UV regions. Importantly, the OMCD effect is relatively insensitive to film thickness, underscoring the robust nature of Cr2Te3 as a material with a high Tc and substantial spin polarization. These properties position Cr2Te3 as an ideal candidate for vdW heterostructure-based spintronic applications. The SQUID, XMCD, OMCD results will be discussed in details.